E-mail is currently one of the most popular applications in computer network. Especially with the development of Internet, e-mail has become one part of people's daily life and an important means of business communication. Therefore, in the traffic of the whole computer network, transporting information of e-mail's occupies a considerable proportion.
In order to make full use of the limited network bandwidth resources, people have proposed a lot of methods to reduce e-mail traffic, for example, compressing e-mail content, etc. For example, U.S. Pat. No. 6,112,227 entitled “FILTER-IN METHOD FOR REDUCING JUNK E-MAIL” by Jeffrey Nelson Heiner, filed on Aug. 6, 1998 and issued on Aug. 29, 2000, has disclosed a method for filtering junk e-mail's, thereby reducing the burden of network traffic and eliminating the burden of the unexpected junk e-mail's for e-mail users. The content thereof is incorporated for reference.
However, during the communicating process of using e-mail's, it always generates a reply-chain: provided that, sending an e-mail e1 from user A to user B, and user B replying user A with an e-mail e2, then the e-mail e2 received by user A containing the whole content of e-mail e1. In fact, e1 has been in the computer of user A. Thereby it causes the waste of time for transporting e-mail's and memory devices. If user A replies the e-mail e2, with the increase of times of to-and-fro in the reply-chain, the waste thereof will exponentially increase. It is well known that the reply-chain universally exist in the communicating process of using e-mail's and the times of to-and-fro in the reply-chain is very large. Therefore, there is a need to develop a method and apparatus to decrease the waste.